I recently discovered a huge collections of first and early editions of Liszt scores at JUILCAT. Really rare scores and editions that are barelly available anywhere else. The server is slow and the files are kind of huge (Transcendental Etudes are over 200 mb[!]) but the rarity and quality of the scores is definitely worth the trouble. Everyone is encouraged to volunteer!
See the project page for details: http://imslp.org/wiki/IMSLP:Community_P ... t_Editions
Anyone who is interested, reply here or put your names directly on the project page.